The progressive implementation of the Urban Waste Water Treatment Directive 91/271/EEC in all Member States isincreasing the quantities of sewage sludge requiring disposal: as reported in [1], in the EU-27, the current practices forsewage sludge disposal are landfill (18%), thermal treatment\incineration (23%), composting (7%), agricultural use (45%)and others re-uses (7%). Urban waste water and b ...